Hide-stretching clamp



Patented Jan. 18, 1944 HIDE-STRETCHING CLAMP Charles F. Fitzgerald, Beverly, Mass, assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application October 27, 1942, Serial No. 463,511

14 Claims.

This invention relates to clips orother work clamping and holding devices and is illustrated as embodied in a clip for holding a hide or skin in stretched condition during drying thereof. While the invention is illustrated as embodied in a device for use in stretching hides andskins, it is to be understood that in various novel and useful aspects the invention is not limited to devices of the illustrated type.

As heretofore constructed, clips for holding hides and skins during drying thereof have commonly included, as an important element thereof, a lever member to engage and clamp the edge of the work piece in such manner as to adjust the clip to variations in the thickness of the portion being clamped. In those cases where the clamped portion of the work piece is unusually thin there may be failure to engage the work piece with suflicient pressure to hold the latter while, on the other hand, thick pieces may require such an effort in closing the clampin lever as to slow up the operator and in time result in damage to the clip through unusual wear and bending or other distortion of the parts. Where attempt is made to overcome these objections by providing a yielding element or elements to engage one surface of the work piece, it is possible in such prior constructions to secure only fair results while the parts are new and then only through the provision of a relatively complicated structure, costly to make and maintain in good condition. 7

It is an object of this invention to provide a clip of the kind described having relatively few parts, and one which will operate with a minimum of wear, and provide a highly effective device for the purpose intended.

To these ends and in accordance with an important feature of the invention, means, including a wedge, is provided to effect closure of the jaws of the clip on a work piece in a manner most eifectively to accommodate the clip to var iationsin the thickness dimensions of the work pieces undergoing treatment. Convenently, the wedge member may be operated by a spring and/or by a finger piece to initiate the clamping operation and to give the preliminary stretching to the hide or skin, the effect of the wedge being such that the firmer the skin is stretched the greater the clamping action, whereby the hide or skin is securely held in place on the stretching frame. It is a further important feature of the invention that the work piece is gripped more firmly during shrinkage due to drying thereof, the wedge operating under these conditions to press the jaws of the clip more firmly toward each other.

These and other important features of the in vention and novel combinations of parts willnow be described in detail in the specification and then pointed out more particularly in the appended claims.

In the drawing, Fig. 1 is a view, partly in side elevation and partly in section, of the novel clipof the present invention, showing the clip ready for use, Fig. 2 is a view similar to Fig. 1 showing the clip engaged with a marginal portion of a hide or skin;

Fig. 3 is a sectional view along the line III--III of Fig. 1 but on a substantially larger scale;

Fig. 4 is an end view of the and Fig. 5 illustrates a species which is simpler in construction, since it omits the self-adjusting feature of the clip shown in Figs. 1 to 3, inclusive.

Upon reference to Figs. 1 to 3, inclusive, it will be seen that the clip, which is specially designed to engage and hold a hide or skin portion during drying of the latter, comprises a main frame or body part 6 having rigidly secured thereto an upper stationary jaw 8 carried between sidewalls ll] of the body part. There is also a bottom wall or floor l2 for slidably supporting a wedge member I4 utilized in lifting and lowering a movable jaw l6 toward and from the upper jaw 8 to grip a portion of a work piece, such as that indicated at |8 (Fig. 2), and to release the same. The gripping and holding effect of the two jaws is increased by the provision of serrations [9 on the work engaging surface of the lower'jaw 116.

To facilitate operation of the wedge l 4, a finger loop 20 is provided which is either fixedly secured to the wedge member M. or made integral therewith as in the construction shown. Obviously a pull upon the finger loop 20 toward the left in Figs. 1 and 2 will result inlifting the lower jaw 16 to effect gripping of the work piece [8. As indicated, the jaw I6 is limitedto 'vertical movement by pins |9a secured to'therear part of the jaw I6 and slidable in vertical slots ZIinthesidewallslD.

To hold the combined wedge member l l'and loop 20 in assembled relation with respect to the body part 6 of the clip there is provided, in the construction illustrated in Figs. 1 and 2, a latch 22 having an upturned end portion 23; the body part 6 beingislotted at 24 to receive the upturned end portion'23. Conveniently't'he latch 22ls se bolt 32 of Fig. 3;

cured to a forwardly extending portion 25 of the loop 20 by means of a spring member 26, the latch 22 having a finger piece 28 extending rearwardly therefrom so that the latch may be readily released from the body portion 6 simply by upward pressure on the finger piece 28 accompanied by a corresponding downward pressure on the adjacent portion 25 of the loop 20. thus releasing the latch 22 from the body portion 6, the loop 20 and wedg I4 may be moved to the left relatively to the body portion to actuate the lower jaw member I B.

Preferably, and as shown, means is provided to move the finger loop 20 and wedge M toward.

the left in Figs. 1 and 2 upon releasing the latch 22 from the body part 6 of the clip, said-means Upon a spect to the work piece, it is obvious that the pring may be omitted, as shown in Fig. 5, in which case the operator must manipulate the combined loop 20 and wedge member M to cause engagement of the work piece through upward movement of the lower jaw i5. To facilitat this manipulation of the loop and wedge member by the operator, there is conveniently provided a thumb rest 50 extending upwardly from the upper wall of the body part 53 of the clip. This enable the operator to efiect preliminary engagementof th clip with respect to the work piece utilizing only one hand for the purpose. For holding the finger piece and wedge 14 in adjusted relation with respect to the body part 5 ofthe clip, the finger loop 26 has its forbeing conveniently in the form of a relatively 1 strong spring 30 of the clock type,'said spring having one end secured to a cylindrical bolt 32 upon which the spring is wound and its other end secured to the combined finger loop 29 and 'wedge member l4. Hence, as soon as the latch 22 is released, the spring 30 retracts th wedge l4 and thus operates the lower jaw 16 with its serrations 19 into work gripping relation with respect to the upper jaw 8. It will'be readily understood that, upon shoving the wedgemember [4 to the right in Figs. 1 and 2 by pressure upon the finger loop 20, the work piece is released and the spring 30 is'rewound. Incidentally, this makes it necessary to shove the finger loop 20 and the wedge l4 far enough to the right in said Figs. 1 and 2 to reengage the latch 22 with the body part 6 at the slot 24. The last-described movement of theloop 20 and wedge I4 normallytakes place to release the workpiece at the end of a drying operation upon the hide or skin, it bein understood inf/his connection that many clips are used to engage different portions ofthe hide or skin and stretch these portions in various directions, the purpose being to secure the hide or skin in stretched condition upon a foraminous stretcher frame where the-hide or skin is left to dry. I

In order to hold the clip in its adjusted relation to the stretcher frame, the body part 6 of the clip is provided with a hook member 36 which may be readily engaged one'of the openings or slots of the foraminous frames provided for stretching hides and skins. Y

To facilitate assembling of the spring 30 with the body part of the clip and also the initial tensioning of the spring, the cylindrica1 bolt 32 is provided with-a square-shouldered end 42 (Figs. 3 and '4) receivable in a correspondingly'shaped opening in one of the side walls It. The other end of the bolt'32has a reduced screw threaded portion 44 rotatably receivable in an opening in the other side wall I0 and projecting beyond the sameso that a nut 46 may be applied to re-' tract the bolt 32 toward the left in Fig. 3 and hold it in properly assembled relation to the side walls of the body part 6. Upon loosening the nut 46, the bolt 32 may bemoved to the right in Fig. 3 until the shouldered portion &2 is displaced completely out of its'socket or slot so that. it may be rotated by application of the proper tool to tension the spring 30, the bolt being held by the tool at the end of the tensioning operation in a position such that the shouldered portion 42 may reenter its socket upon tightening the nut 46.

While, in the preferred species of the invention, spring. means is provided to give the initial setting 'or clamping action of the clip with Trewardly projecting end 56 provided with a rounded tooth element 52 to engag slidably and adjustably and in a selective manner with any one of the corrugations 5 3 on the lower face of the upper wall'of the body part 6. V I

In stretching a hide or skin with theaid of clips of the construction shown in'Figs. 1, 2 and 3 of the drawing, the operator positions the clip with the upper jaw 8 thereof engaging the upper or grain surface of the hide or skins at a marginal portion thereof and then presses the finger piece 28 and'the adjacent portion 25 of the loop member 20 toward each other,-thereby effecting release of the latch 2.2,from its slot 24. Such release of the latch 22 permits the spring 30 to operate the wedge 14 and thus efiect upward movement of the jaw 16 into clamping relation with respect to the margin of the Work piece and the upper jaw 8, it being understoodthat the other hand of the operator holdsthe body part '6 of the clip in selected relation to the margin of the work piece. Having thus effected preliminary engagement of the clip with respect to the workpiece, the operator pulls-on'the fin'ger loop 20 tostretch the work piece, such pulling on the loop member 20 having the effect 'alsoyof further tightening'the grip of the jaws on the work piece through the action'of the wedge -I' l,so that'by the time the work piece is properly stretched in its engaged ter is located with respect to the stretcher frame by engaging the hook member 36 inone of the openings or slo'ts therein. During drying of the work piece such as a hide or-skin, the latter shrinks in area and to some extent in thickness. However, the clip does not lose-its hold since, during anyshrinkagein thickness, 'the wedge 14 maintains thegrip of'the lower jaw throughlfurther'pull of the springtlfl. When it isde'sired'to release the work piece, theoperator shovesto the right on the finger loop 26 thereby moving the wedgeto the right and permitting the lower jaw It to drop away "from'the work piece and to release it, this movement 'of'the finger loop 20 enact the wedge 'Hl taking .placewhile the body part '6 of the clip is'held'stationarybecause ofthe engagement of the hook member 38 with the stretcher frame.

The operation of the clip shown-in Fig. 5 is very similar to thatjust described, the'only difference being that the operator must give the preliminarymovement'of the wedge relative to the body-partB -of the clip, by proper'manipulation ofthe finger 'loop- 20 in relation to the thumb rest 50 on the body part of the clip.

Having described my invention, .what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a clamping device, the combination with a pair of gripper jaws, one of said jaws being loosely mounted on said device, of a finger piece for positioning said device in operative relation to a work piece, said finger piece being releasable at will for movement relatively to said gripper jaws and having a portion formed as a wedge to operate said gripper jaws to grip or release the work piece'in response to such movement of the finger piece, said wedge being arranged to increase the pressure of said gripper jaws on the work in response to a pull of said device on the work.

2. In a clamping device, a body member, an upper jaw on said body member, a lower loosely mounted jaw, and a wedge member in contact with the body member and beneath said lower jaw, said wedge member being operative to cause relative approaching movement of the jaws with respect to each other, upon relative sliding movement of the jaws and said wedge member, whereby a portion of a work piece. is gripped and an increase of the clamping pressure of the jaws on the work is effected by the action of said wedge member in response to the pull of said device on the work.

3. In a clamping device, a main body member, an upper jaw on said body member, a lower jaw, a movable wedge member slidable on said body member and operative to control relative approaching and separating movements of the jaws with respect to each other, and a finger loop piece to operate the movable wedge, the arrangement being such that a pull on the finger loop piece away from a work piece placed between the jaws operates the wedge member to cause firm clamping action of the jaws against a portion of such work piece.

4. In a clamping device for gripping a work piece, an upper jaw, a lower jaw, a movable wedge member to control relative approaching and separating movements of the jaws with respect to each other, a finger piece to operate the movable wedge member, and a latching device to hold the wedge member in its initial position in which the jaws are spaced substantially from each other, said latching device being readily operable to release the wedge member so that the latter may be operated to cause clamping pressure of the jaws on the work piece.

5. In a clamping device for gripping a work piece, an upper jaw, a lower jaw, a movable wedge member to control relative approaching and separating movements of the jaws with respect to each other, a finger piece for moving the wedge member, a latching device associated with the finger piece for holding the wedge member against movement out of initial position in which the lower jaw is spaced substantially from the upper jaw, said latching device being readily operable to release the wedge member so that the latter may be operated to cause clamping pressure of the jaws on the work piece, and a spring means for thus operating the movable wedge member upon release of the finger piece by said latch device. 1

6. In a clamping device for gripping a work piece, an upper jaw, a lower jaw, a movable wedge member to control relative approaching and separating movements of the jaws with respect to each other, and a finger piece to operate the movable wedge member, the arrangement being such that-a pull on the finger piece away'from a work piece placed between the jawsoperates the wedge member to cause clamping pressure of the jaws upon a portion of such work piece, said clamping device having a hooked portion to engage a work piece stretching frame and to retain the clamping device on said frame against the pull of the tensioned work piece, said finger piece and wedge member being movable by a push on the finger piece against the resistance of the frame to release the clamping pressure. I

7. In a clamping device for gripping a work piece, a main frame, an upper jaw on said main frame, a lower movable jaw having a serrated,

work, engaging surface, and a movable wedge member between a portion of the main frame and the lower jaw for moving the lower jaw toward the upper jaw whereby a portion of a work piece may be gripped.

8. In a clamping device for gripping a work piece, a main frame, an upper jaw on said main frame, a lower movable jaw, a movable wedge member to lift the lower jaw toward the upper jaw and away from a portion of the main frame, and a finger piece secured to the movable wedge member, the arrangement being such that a pull on the finger piece away from the jaws operates the wedge member to press the lower jaw firmly against a portion of such work piece interposed between the jaws.

9. In a clamping device for gripping a work piece, a main frame having a fixed upper jaw, a lower jaw movable toward and from the upper jaw, a movable wedge member to lift the lower jaw toward the upper jaw, a finger piece secured to the movable wedge member, and a latching device associated with the finger piece to hold the wedge member in its initial position in which the lower jaw'is spaced substantially from the upper jaw, said latching device being readily operable to release the finger piece so that the wedge member may be operated to press the lower jaw toward the upper jaw.

10. In a clamping device for gripping a work piece, a main frame having a fixed upper jaw, a lower jaw movable toward and from the upper jaw, a movable wedge member to lift the lower jaw toward the upper jaw, a finger piece secured to the movable wedge member, a latching device associated with the finger piece to hold the wedge member in its initial position in which the lower jaw is spaced substantially from the upper jaw, said latching device being readily operable to release the finger piece so that the wedge member may be operated to press the lower jaw toward the upper jaw, and spring means for thus operating the movable wedge member upon release of the finger piece by said latch device.

11. In a clamping device, a main frame, an upper jaw fixed to said main frame, a lower movable jaw, a movable wedge member to lift the lower jaw toward the upper jaw, and a finger piece arranged to operate the movable wedge member, the arrangement being such that a pull on the finger piece away from the jaws operates the wedge member to close the jaws upon a work piece interposed between the jaws, said main frame having a hooked portion to retain the clamping device upon a work piece stretching frame against the tension of such work piece, and said finger piece and wedge member being movable relatively to said jaws by a push on said finger piece against the resistance of the stretching frame to open the said jaws.

12. In a clamping device, a main frame having a fixed jaw, a loosely mounted jaw having serrations on its work engaging face, said loosely mounted jaw being arranged parallel to the fixed jaw and being mounted for free normal movement toward said fixed jaw, a wedge member between the loosely mounted jaw and a portion of the main frame for moving said movable jaw to close the jaws on a work piece, anda finger piece .for thus operating said wedge member by a pull in a direction away from said workpiece.

13. In a clamping device, 'a main frame having a passage therethrough, one end of said passage having a wall to constitute a fixed .jaw, a loosely mounted jaw arranged to face said fixed jaw, a wedge member between another wall of said one end of said passage and the loosely mounted jaw,

and a'finger piece inserted within the other end of the said passage and attached to the wedge member, said finger piece being adapted to open or close thejaws by means of the wedge member.

14. In a clamping device, a main frame having a fixed jaw and a portion parallel to said fixed jaw, a finger loop piece slidably engaging the mainframe, a wedge member also slidable on the main frame and under the control of said finger loop piece, and a secondjaw movable relative to the first jaw, saidwedge member being interposed between said second jaw and said portion of the main frame, the arrangement being such that a push on the finger loop piece toward the jaws will serve to open the jaws.

CHARLES F. FITZGERALD. 

